diff --git a/segmentio.go b/segmentio.go
index 457a8d8..8860d6e 100644
--- a/segmentio.go
+++ b/segmentio.go
@@ -47,7 +47,6 @@ type publication struct {
 	msg        *broker.Message
 	ackCh      chan map[string]map[int]int64
 	readerDone *int32
-	ackChMu    sync.Mutex
 }
 
 func (p *publication) Topic() string {
@@ -62,9 +61,7 @@ func (p *publication) Ack() error {
 	if atomic.LoadInt32(p.readerDone) == 1 {
 		return fmt.Errorf("kafka reader done")
 	}
-	p.ackChMu.Lock()
 	p.ackCh <- map[string]map[int]int64{p.topic: {p.partition: p.offset}}
-	p.ackChMu.Unlock()
 	if cerr := p.ackErr.Load(); cerr != nil {
 		return cerr.(error)
 	}
@@ -459,14 +456,32 @@ func (k *kBroker) commitLoop(generation *kafka.Generation, commitInterval time.D
 
 	go func() {
 		defer func() {
-			for _, errCh := range errChs {
-				close(errCh)
-			}
 			close(commitDoneCh)
 		}()
 
+		checkTicker := time.NewTicker(300 * time.Millisecond)
+		defer checkTicker.Stop()
+
 		for {
 			select {
+			case <-checkTicker.C:
+				if atomic.LoadInt32(cntWait) == 0 {
+					//fmt.Printf("cntWait IS 0\n")
+					mapMu.Lock()
+					if len(offsets) > 0 {
+						if err := generation.CommitOffsets(offsets); err != nil {
+							for _, errCh := range errChs {
+								errCh <- err
+							}
+							return
+						}
+					}
+					mapMu.Unlock()
+					if k.opts.Logger.V(logger.TraceLevel) {
+						k.opts.Logger.Trace(k.opts.Context, "stop commit loop")
+					}
+					return
+				}
 			case ack := <-ackCh:
 				if k.opts.Logger.V(logger.TraceLevel) {
 					k.opts.Logger.Tracef(k.opts.Context, "new commit offsets: %v", ack)
@@ -510,7 +525,6 @@ func (k *kBroker) commitLoop(generation *kafka.Generation, commitInterval time.D
 					if k.opts.Logger.V(logger.TraceLevel) {
 						k.opts.Logger.Trace(k.opts.Context, "stop commit loop")
 					}
-
 					return
 				}
 				//fmt.Printf("cntWait NOT 0\n")
@@ -569,8 +583,6 @@ func (h *cgHandler) run(ctx context.Context) {
 		h.brokerOpts.Logger.Trace(ctx, "start partition reader")
 	}
 
-	var ackChMu sync.Mutex
-
 	td := DefaultStatsInterval
 	if v, ok := h.brokerOpts.Context.Value(statsIntervalKey{}).(time.Duration); ok && td > 0 {
 		td = v
@@ -584,16 +596,11 @@ func (h *cgHandler) run(ctx context.Context) {
 	defer func() {
 		atomic.AddInt32(h.cntWait, -1)
 
-		ackChMu.Lock()
-		if atomic.CompareAndSwapInt32(h.readerDone, 0, 1) {
-			close(h.ackCh)
-		}
-		ackChMu.Unlock()
+		atomic.CompareAndSwapInt32(h.readerDone, 0, 1)
 		if err := h.reader.Close(); err != nil && h.brokerOpts.Logger.V(logger.ErrorLevel) {
 			h.brokerOpts.Logger.Errorf(h.brokerOpts.Context, "[segmentio] reader close error: %v", err)
 		}
 		<-h.commitDoneCh
-		//fmt.Printf("<-h.commitDoneCh\n")
 		if h.brokerOpts.Logger.V(logger.TraceLevel) {
 			h.brokerOpts.Logger.Trace(ctx, "stop partition reader")
 		}
@@ -642,7 +649,7 @@ func (h *cgHandler) run(ctx context.Context) {
 			if h.subOpts.ErrorHandler != nil {
 				eh = h.subOpts.ErrorHandler
 			}
-			p := &publication{ackCh: h.ackCh, partition: msg.Partition, offset: msg.Offset + 1, topic: msg.Topic, msg: &broker.Message{}, readerDone: h.readerDone, ackChMu: ackChMu}
+			p := &publication{ackCh: h.ackCh, partition: msg.Partition, offset: msg.Offset + 1, topic: msg.Topic, msg: &broker.Message{}, readerDone: h.readerDone}
 
 			if h.subOpts.BodyOnly {
 				p.msg.Body = msg.Value
diff --git a/stats.go b/stats.go
index 06ae7cc..ef7471e 100644
--- a/stats.go
+++ b/stats.go
@@ -2,7 +2,6 @@ package segmentio
 
 import (
 	"context"
-	"fmt"
 	"time"
 
 	kafka "github.com/segmentio/kafka-go"
@@ -16,7 +15,7 @@ func readerStats(ctx context.Context, r *kafka.Reader, td time.Duration, m meter
 	for {
 		select {
 		case <-ctx.Done():
-			fmt.Printf("done reader stats\n")
+			//fmt.Printf("done reader stats\n")
 			return
 		case <-ticker.C:
 			if r == nil {